// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include "test_stacktrace_build_id.skel.h"

void test_stacktrace_build_id_nmi(void)
{
        int control_map_fd, stackid_hmap_fd, stackmap_fd;
        struct test_stacktrace_build_id *skel;
        int err, pmu_fd;
        struct perf_event_attr attr = {
                .freq = 1,
                .type = PERF_TYPE_HARDWARE,
                .config = PERF_COUNT_HW_CPU_CYCLES,
        };
        __u32 key, prev_key, val, duration = 0;
        char buf[BPF_BUILD_ID_SIZE];
        struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
        int build_id_matches = 0, build_id_size;
        int i, retry = 1;

        attr.sample_freq = read_perf_max_sample_freq();

retry:
        skel = test_stacktrace_build_id__open();
        if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
                return;

        /* override program type */
        bpf_program__set_type(skel->progs.oncpu, BPF_PROG_TYPE_PERF_EVENT);

        err = test_stacktrace_build_id__load(skel);
        if (CHECK(err, "skel_load", "skeleton load failed: %d\n", err))
                goto cleanup;

        pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
                         0 /* cpu 0 */, -1 /* group id */,
                         0 /* flags */);
        if (pmu_fd < 0 && (errno == ENOENT || errno == EOPNOTSUPP)) {
                printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n", __func__);
                test__skip();
                goto cleanup;
        }
        if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n",
                  pmu_fd, errno))
                goto cleanup;

        skel->links.oncpu = bpf_program__attach_perf_event(skel->progs.oncpu,
                                                           pmu_fd);
        if (!ASSERT_OK_PTR(skel->links.oncpu, "attach_perf_event")) {
                close(pmu_fd);
                goto cleanup;
        }

        /* find map fds */
        control_map_fd = bpf_map__fd(skel->maps.control_map);
        stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap);
        stackmap_fd = bpf_map__fd(skel->maps.stackmap);

        if (CHECK_FAIL(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null")))
                goto cleanup;
        if (CHECK_FAIL(system("taskset 0x1 ./urandom_read 100000")))
                goto cleanup;
        /* disable stack trace collection */
        key = 0;
        val = 1;
        bpf_map_update_elem(control_map_fd, &key, &val, 0);

        /* for every element in stackid_hmap, we can find a corresponding one
         * in stackmap, and vice versa.
         */
        err = compare_map_keys(stackid_hmap_fd, stackmap_fd);
        if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap",
                  "err %d errno %d\n", err, errno))
                goto cleanup;

        err = compare_map_keys(stackmap_fd, stackid_hmap_fd);
        if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap",
                  "err %d errno %d\n", err, errno))
                goto cleanup;

        build_id_size = read_build_id("urandom_read", buf, sizeof(buf));
        err = build_id_size < 0 ? build_id_size : 0;

        if (CHECK(err, "get build_id with readelf",
                  "err %d errno %d\n", err, errno))
                goto cleanup;

        err = bpf_map__get_next_key(skel->maps.stackmap, NULL, &key, sizeof(key));
        if (CHECK(err, "get_next_key from stackmap",
                  "err %d, errno %d\n", err, errno))
                goto cleanup;

        do {
                err = bpf_map__lookup_elem(skel->maps.stackmap, &key, sizeof(key),
                                           id_offs, sizeof(id_offs), 0);
                if (CHECK(err, "lookup_elem from stackmap",
                          "err %d, errno %d\n", err, errno))
                        goto cleanup;
                for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i)
                        if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID &&
                            id_offs[i].offset != 0) {
                                if (memcmp(buf, id_offs[i].build_id, build_id_size) == 0)
                                        build_id_matches = 1;
                        }
                prev_key = key;
        } while (bpf_map__get_next_key(skel->maps.stackmap, &prev_key, &key, sizeof(key)) == 0);

        /* stack_map_get_build_id_offset() is racy and sometimes can return
         * BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID;
         * try it one more time.
         */
        if (build_id_matches < 1 && retry--) {
                test_stacktrace_build_id__destroy(skel);
                printf("%s:WARN:Didn't find expected build ID from the map, retrying\n",
                       __func__);
                goto retry;
        }

        if (CHECK(build_id_matches < 1, "build id match",
                  "Didn't find expected build ID from the map\n"))
                goto cleanup;

        /*
         * We intentionally skip compare_stack_ips(). This is because we
         * only support one in_nmi() ips-to-build_id translation per cpu
         * at any time, thus stack_amap here will always fallback to
         * BPF_STACK_BUILD_ID_IP;
         */

cleanup:
        test_stacktrace_build_id__destroy(skel);
}